气相色谱-高分辨质谱法定性筛查小麦面粉中农药残留

Qualitative screening of pesticide residues in wheat flour by gas chromatography-high resolution mass spectrometry

中文关键词:  农药残留  气相色谱-高分辨质谱法  定性筛查  小麦面粉

英文关键词:pesticide residuals  gas chromatography-high resolution mass spectrometry  qualitative screening  wheat flour

中文摘要:

      目的 开发和验证用于小麦面粉中农药残留定性筛查的气相色谱-高分辨质谱方法。方法 小麦面粉样品在乙腈和柠檬酸缓冲液中混匀, 加入硫酸镁和氯化钠进行盐析, 混匀静置后完成液液萃取。上清液经过N-丙基乙二胺和C18官能团净化除去杂质, 硫酸镁去除水分后进行氮吹浓缩, 再注射入气相色谱飞行时间质谱仪进行分析, 以全扫描模式进行数据采集。最后通过高分辨质谱数据库比对和质谱工作站的自动积分完成筛查工作。结果 气相色谱-飞行时间质谱法提供了全面准确的离子扫描结果, 当截断值为20%, 400种农药都能在4 μg/kg的水平下得到正确的筛查结果, 其中假阴性和假阳性率都低于5%。结论 该方法实现了高通量的农药残留筛查, 结果准确, 适用于小麦面粉样品中的挥发性、半挥发性农药残留的多组分筛查。

英文摘要:

      Objective To develop and validate a gas chromatography-high resolution mass spectrometry-based method for qualitative screening of pesticide residues in wheat flour. Methods Wheat flour samples were mixed in acetonitrile and citric acid buffer, magnesium sulfate and sodium chloride were then added for salting, and the liquid-liquid extraction was completed after mixing and standing. Then the supernatant was purified by N-propyl ethylenediamine and C18 functional group to remove impurities and magnesium sulfate to remove water. Then the supernatant was concentrated under nitrogen and injected into the gas chromatography-time-of-flight mass spectrometry for analysis. Data acquisition was performed in full scan mode. Finally, the screening was completed by database comparison and automatic integration of mass spectrometry workstation. Results Gas chromatography-high resolution mass spectrometry provided comprehensive and accurate ion scan results. When the cut-off value was set to 20%, 400 kinds of pesticides could get correct screening results at the level of 4 μg/kg, with a false negative and false positive rate of less than 5%. Conclusion The method enable high throughput screening of pesticides residues with accurate results and is suitable for multi-residuals screening of volatile and semi-volatile pesticide residues in wheat flour samples.